It is known to measure tension in a rope or cable by means of a tensiometer, which is a device for determining the tensile strength of materials. Cables that must be tested include, for example, those used as a control cable in an aircraft. In a known device of this type the rope or cable is supported or held between two spaced supports. The spacing between the supports is known and the testing force is applied in a direction perpendicularly to a straight line interconnecting the supports, and centrally therebetween. The applied force deflects the rope or cable away from the straight line. Based on this deflection in combination with calibration tables, it is possible to determine the tension in the rope or cable.
The conventional approach as described above is subject to a measuring error because the tension in the rope or cable is increased by the force applied for the measuring and the error depends on the stiffness and length of the rope or cable between the supports. This increase of the tension in the rope or cable by the measuring force, as compared to the tension prior to the application of the measuring force is undesirable, due to said error. Additionally, the evaluation depends on the calibration table provided by the manufacturer, either of the rope or cable or by the aircraft manufacturer or other manufacturer of a device in which a rope or cable needs to be tested. It can happen that the calibration table is not available when needed.